The U.S. Environmental Protection Agency on Dec. 6 proposed revisions to the greenhouse gas (GHG) emission standards for new, modified, and reconstructed coal-fired power plants.
If finalized, the proposed revised standards would apply to new, modified, and reconstructed sources after the date the proposed rule is published in the Federal Register.
EPA Acting Administrator Andrew Wheeler unveiled details of the proposed revisions during a news conference held in Washington, D.C.
EPA is proposing to revise its 2015 best system of emission reduction (BSER) for coal-fired power plants. The 2015 rule determined BSER for coal fired units based on partial carbon capture and storage (CCS). The revised rule amends the BSER determination based on EPA’s updated analysis of reasonable cost and the geographic availability of CCS.
For large coal units, the proposed BSER is super-critical steam generation technology. The proposed emission rate would be 1,900 pounds of carbon dioxide (CO2) per megawatt hour on a gross output basis (lbs CO2/MWh-gross).
For smaller coal units, the proposed BSER is subcritical steam generation technology. The revised emission rate would be 2,000 lbs CO2/MWh-gross.
For coal-refuse fired units, the proposed BSER is best available subcritical steam generation technology. The proposed emission rate would be 2,200 lbs CO2/MWh-gross regardless of the unit’s capacity.
And for reconstructed fossil fuel -fired steam units, EPA is revising the performance standard based on the most efficient demonstrated steam cycle. A unit-specific emission limit will be determined by the unit’s best historical annual CO2 emission rate.
For now, the federal agency is not proposing to change the standards of performance for newly constructed or reconstructed stationary combustion turbines.
However, EPA is taking comment on whether and how to address concerns raised by stakeholders regarding the increased use of simple cycle aeroderivative turbines, including as back-up generation for wind and solar resources, whose operation may exceed the non-base load threshold described in the 2015 rule.
EPA said that any follow-up regulatory actions would be achieved through a separate and subsequent regulatory proposal.
In addition, EPA will take comment on the regulatory threshold under section 111(b) of the Clean Air Act (CAA), that a source category, “causes, or contributes significantly to,” air pollution.
CAA section 111(b)(1)(A) requires the EPA Administrator to establish a list of source categories to be regulated under section 111. A category of sources is to be included on the list ‘‘if in [the Administrator’s] judgment it causes, or contributes significantly to, air pollution which may reasonably be anticipated to endanger public health and welfare.’’
This determination is commonly referred to as an ‘‘endangerment finding’’ and that phrase encompasses both the ‘‘causes or contributes significantly’’ component and the ‘‘endanger public health and welfare’’ component of the determination. Then, for the source categories listed under section 111(b)(1)(A), the Administrator promulgates, under section 111(b)(1)(B), ‘‘standards of performance for new sources within such category.’’
EPA plans to host at least one public hearing on the proposed rule. There will be a 60-day public comment period once the proposal is published in the Federal Register.
Additional information is available here.
CAA requires EPA to establish new source performance standards
The CAA requires EPA to establish new source performance standards (NSPS) for new and modified stationary emission sources that cause air pollution that may endanger public health or welfare.
In December 2010, EPA entered into a settlement agreement to establish NSPS for GHG emissions from electric generating units (EGUs).
In April 2012, EPA proposed NSPS for CO2 emissions from new fossil fuel-fired power plants. The proposed standards under section 111(a) of the Clean Air Act were based on the BSER that EPA had determined to be adequately demonstrated for the emissions source.
In January 2014, EPA published its withdrawal of the proposal, followed by a new proposed rule with separate standards for modern natural gas plants (combined-cycle) and other facilities, chiefly coal-fired plants. In June 2014, EPA proposed CO2 emission standards for modified and reconstructed power plants. As with new plants, EPA proposed separate standards for gas- and coal-fired facilities.
In October 2015, EPA published a final rule establishing NSPS for carbon dioxide emissions for both new and modified power plants.
For new and reconstructed gas-fired plants, under the BSER standard, EPA set the emission limit at 1,000 pounds of CO2 per megawatt‐hour on a gross‐output basis (lb CO2 /MWh‐gross).
EPA declined to issue standards for modified natural gas plants, based on a need to gather further information. For new coal plants, EPA set the emission limit at 1,400 lb CO2/MWh‐gross, based upon a BSER that would include partial CCS. For coal plants making larger modifications, EPA set the CO2 emission limit at the level of the facility’s best historical annual performance during the years dating from 2002 to the time of modification.
EPA declined to set NSPS for coal plants making smaller modifications based, in part, upon a need to gather further information. For reconstructed coal plants, EPA set the emission limit at 1,800 lb CO2/MWh‐gross for sources with heat input greater than 2,000 MMBtu/h, and 2,000 lb CO2/MWh‐gross for sources with a heat input of less than or equal to 2,000 MMBtu/h.
NSPS challenged in court
The NSPS was subsequently challenged in the courts in North Dakota v. EPA (2015). One of the key issues in the case was whether partial CCS is an adequately demonstrated technology for reducing GHG emissions from coal-fired power plants.
On March 30, 2017, the U.S. Court of the Appeals for the D.C. Circuit issued an order to delay oral argument and hold the case in abeyance indefinitely. On August 10, 2017, the court issued another order to continue holding the cases in abeyance pending further action from the administration.
Trump issues executive order
On March 28, 2017, President Trump issued an executive order instructing EPA to review the new source performance standards and to rescind or rewrite the rule as needed to promote the President’s goals of energy independence and economic growth. EPA immediately submitted a request to the D.C. Circuit to hold the case in abeyance pending EPA’s reconsideration of the rule.
On April 4, 2017, EPA published a notice in the Federal Register announcing that it was reviewing and, if appropriate, would initiate proceedings to suspend, revise, or rescind the rule.
